University of Pau and Pays de l'Adour, E2S UPPA, CNRS, IPREM-MIRA, UMR 5254, 64600, Anglet, France.
Sorbonne Université, CNRS, INRAE, IRD, UPD, UPEC, Institute of Ecology and Environmental Sciences - Paris, IEES, 75005 Paris, France.
Environ Sci Process Impacts. 2024 Sep 18;26(9):1571-1587. doi: 10.1039/d4em00351a.
Galaxolide (HHCB) is the most common synthetic musk compound detected in numerous daily products. Despite its persistence in the aquatic environment, the photodegradation of HHCB remains poorly understood. In this study, we investigated the direct and indirect photolysis kinetics of HHCB under simulated sunlight and UVC light. Our aim was to determine the role of reactive oxygen species (ROS) responsible for HHCB degradation in the aquatic environment and to identify its transformation products. The influence of environmental factors on indirect photolysis was investigated by testing both synthetic waters (containing humic acid, carbonate (CO), and nitrate (NO)) and real waters (riverine and effluent). Hydrogen peroxide (HO/UVC) was tested to simulate the wastewater treatment process. Quencher experiments were conducted to identify the role of ROS in HHCB photodegradation, including hydroxyl radicals (˙OH), carbonate radicals (CO˙), triplet states of dissolved organic matter (DOM*), and singlet oxygen (O). The results clearly indicated that HHCB was efficiently degraded by direct photolysis under both light conditions. The presence of HO led to the most efficient HHCB degradation due to the high production of ˙OH induced under UVC. Indirect photolysis contribution was observed, induced by ˙OH, CO˙, DOM*, and O to different extents depending on the light and matrix composition. The experiments led to the detection of transformation products: HHCB lactone, a well-known transformation product, and two other substances with proposed structures. This study provides a comprehensive identification of the processes involved in the direct and indirect photodegradation of HHCB, which could serve as the basis for evaluating and modeling the fate of HHCB in aquatic environments.
加洛麝香（HHCB）是在许多日常产品中检测到的最常见的合成麝香化合物。尽管它在水生环境中具有持久性，但 HHCB 的光降解仍然知之甚少。在这项研究中，我们研究了 HHCB 在模拟阳光和 UVC 光下的直接和间接光解动力学。我们的目的是确定负责水生环境中 HHCB 降解的活性氧物质（ROS）的作用，并确定其转化产物。通过测试合成水（含有腐殖酸、碳酸盐（CO）和硝酸盐（NO））和实际水（河流和废水），研究了环境因素对间接光解的影响。测试了过氧化氢（HO/UVC）以模拟废水处理过程。进行猝灭实验以确定 ROS 在 HHCB 光降解中的作用，包括羟基自由基（˙OH）、碳酸根自由基（CO˙）、溶解有机物的三重态（DOM*）和单线态氧（O）。结果清楚地表明，HHCB 在两种光照条件下都能通过直接光解有效地降解。由于 UVC 下诱导产生的˙OH 大量生成，HO 的存在导致 HHCB 降解效率最高。观察到间接光解的贡献，这是由˙OH、CO˙、DOM*和 O 不同程度诱导的，这取决于光照和基质组成。实验导致了转化产物的检测：HHCB 内酯，一种众所周知的转化产物，以及另外两种具有提议结构的物质。这项研究提供了对 HHCB 直接和间接光降解过程的全面识别，这可以为评估和模拟 HHCB 在水生环境中的命运提供基础。
